<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<style>
  [class] {
    background-color: skyblue;
  }
</style>

<body>

  <div id="root" v-clock class="qq">
    <h2>DEMO</h2>
  </div>
  <div id="demo">
    <h2>Hello</h2>
  </div>

</body>

</html>